lovely shot, thanks for sharing! here are just a couple of quick observations:

1. The whites are a bit 'off white' more greyish. This can easily be bumped up by using a bit more contrast/curves/levels in photoshop.
2. I would person take out the green leaf on the bottom of the frame and at the bottom of the right handflower (including stem). You should be able to 'burn' them out.

You can also probably create a b&amp;w layer ontop of the orginal image and erase the stamen to leave the only bit of colour in. It may help help in this image to get the whites whiter.